1. [Industrial Application]
The present invention relates to a method for producing metal fibers, and more particularly ultra fine and short metal fibers which are suitable to using as bases of composite materials.
2. [Prior Art and Problems]
The metal fibers have, in comparison with non metallic fibers, excellent properties of high elasticity, bendability, abrasion resistance, electric or heat conductivity, wettability or sintering property, and so they have been used as composite bases for mixing heterogeneous materials.
The metal fibers are generally divided into long and short ones. The former is mainly used to the base of composite material strengthened by fibers for increasing strength of a structure, and the latter is utilized as the base of the composite material strengthened by dispersing grains for aiming at an intermediate nature of strengthening by the fibers and strengthening by the grains.
Metal fibers have been desired to have small cross section as powders for composite and have proper lengths (aspect ratio) and to be mass-produced at low cost because of much use. However there has not been conventionally a method for producing ultra fine and short metal fibers, which was practical for accomplishing desires as said above.
As the fine and short metal fibers and a production therefor, whiskers are known, but as the production is technically difficult and productivity is poor, and its dispersion in liquid substance is not preferable, it has scarcely been used. Another process is extracting the materials from a molten metal, drawing line materials and cutting long fibers into short ones. Depending upon this process, the fibers are fragile and the sizes or physical properties are irregular, and those have not been suitable for using as the base of the composite matreials.